The inventions described herein relate to dissolving gas in liquids, e.g., carbonation, for use in preparing a beverage. Systems for carbonating liquids and/or mixing liquids with a beverage medium to form a beverage are described in a wide variety of publications, including U.S. Pat. Nos. 4,025,655; 4,040,342; 4,636,337; 6,712,342 and 5,182,084; and PCT Publication WO 2008/124851.